The answer to this question can be perhaps available from the 87th stramza of "Yashstilakchulikc" scripture written by Acharya Somdev Suri.
He observes:
There are indefinite number of Graha (Planet) – Nakshatra – Taras (Stars) (Heavenly elements in the sky). But their numbers has been shown to be limited by the rule of nature. In the present era of Utsarpini time-span, there are 24 times only when these heavenly elements are positioned in the best location. This is a certainty.
Therefore there are only 24 Tirthankaras only not a one less not a one more.
He observes:
There are indefinite number of Graha (Planet) – Nakshatra – Taras (Stars) (Heavenly elements in the sky). But their numbers has been shown to be limited by the rule of nature. In the present era of Utsarpini time-span, there are 24 times only when these heavenly elements are positioned in the best location. This is a certainty.
Therefore there are only 24 Tirthankaras only not a one less not a one more.
